The present invention relates to sprinkler units, and pertains particularly to a rotary stream sprinkler unit.
In my prior U.S. Pat. No. 3,854,664, issued Dec. 17, 1974, and, entitled "SPRINKLER SYSTEMS", I disclose a sprinkler unit which directs a plurality of rotating streams over an area to be watered. In my prior device, the water flows through an orifice plate and into a rotating head having a plurality of tubular passages for directing the respective streams through a particular arc. The orifice plate of that prior device controls the arc of coverage and is engaged by the rotating head as it rotates to distribute the water.
Among the problems of the prior device is that sand and grit from the water supply get on the orifice plate and rapidly wear the plate and seals of the unit. In some instances, the sand and grit can cause the unit to stall. These and other problems of the prior device have prevented it from being satisfactory.
Accordingly, it is desirable that an improved rotary stream sprinkler unit be available.